Most mainstream distributions, like Ubuntu, Fedora, and Mandriva, have already adopted a time-based release schedule, meaning that releases are not done on a feature basis, but according to a pre-determined time schedule. The Debian project has announced that it has adopted a time-based release schedule too.

I think that desktop linux users are to 'blame', not Shuttleworth although placing blame seems too severe at this point. Fedora, Mandriva and Ubuntu all have 'regular' release intervals and that is what desktop users have come to expect. If anything this move is to bring some Ubuntu users (and other desktop users) to Debian, not to bow to Ubuntu.

Honestly the erratic release cycle of debian is the largest hurdle keeping me away from it.